1. Field of the Invention
The present invention relates to a soybean embryo separation method, and more particularly to a mechanical method for the separation of soybean embryo which is regarded as a functional part of soybeans, from a combination of hull and embryo.
2. Description of the Prior Art
Studies about the abundant nutritional elements and cultivating method of soybeans have been actively conducted since about 1950 because soybean is regarded as a "miracle plant" and "beef out of field".
The main ingredients of soybeans consist of 40% of protein, 20% of fat, carbohydrate and the like, and particularly, soybeans are abundant in physiologically activating substances conducive to maintenance of homeostasis and biorhythm in the human body.
Recently, one of the physiologically activating substances, isoflavone is recognized to have a functional substance such that very many papers on isoflavone in soybeans have been published in the United States during recent years. Particularly, it is reported that a type of isoflavone, genistein, is effective in prevention of mammary cancer, osteoporosis and prostate cancer.
Soybean generally consists of 2% of embryo, 20% of endosperm and 8% of hull. The content of isoflavone in soybeans is approximately 0.2% and it is known that an embryo contains 2%, ten times the amount of isoflavone the endosperm contains.
In order to extract isoflavone, a method is required to extract only part of the embryo, and many technical methods are known relating to processes for separating the embryo from the soybean.
Japanese Patent publication No. 62-100256 discloses a method by which a crushed soybean embryo concentrate is reduced from high temperature and high pressure to low pressure to expand only the embryo to 1.5-5 times and to thereby separate same according to gravity.
Still another Japanese Patent publication No. Sho 59-82063 discloses a method, where soybeans are crushed by a pulverizer to eliminate bigger sizes of hull by an auxiliary peeling machine. The hull is then crushed by crusher to remove the smaller sizes of hull by way of a blower. The hull is now sifted and separated into halved soybeans and embryo.
However, there are problems with these Japanese embryo obtaining methods in that the amount of recovered embryo is low, nutrients in the embryo tend to be destroyed due to expansion of the embryo at high pressure, manufacturing cost can be high and moreover, purity of the embryo can be low.